CN101774138B - Precise centering fixture for repairing back lining bearing - Google Patents

Abstract

A precise centering fixture for repairing back lining bearing is used for repairing back lining bearing. An outer ring is arranged at the outer part of a keeping apparatus; a steel ball is embedded in the window of the keeping apparatus; a deflector rod is connected on a mandrel, and the mandrel is connected with a centering ring through interference fit integrally; one end of a positioning rod is connected with the mandrel and the other end thereof is inserted in the hole of a limiting plate; the limiting plate is connected on one side of the keeping apparatus; a limit stop is connected with one side of the keeping apparatus; a rigid ring is sheathed outside the steel ball in the window of the keeping apparatus; the longitudinal section of the centering ring is dumbbell-shaped, and uniformly distributed circular arcs with alternating wave crests and troughs are arranged at the contact positions of the radial circumferences on the edges of the two sides of the centering ring and the steel ball; and a baffle is connected on the other end of the keeping apparatus. The bearing is sheathed on the mandrel, the outer ring of the back lining bearing is accurately positioned on the mandrel through the elastic approach amount of the precise steel ball; enough load is used for bearing the grinding force in the tangential direction for grinding the outside diameter of the bearing sleeve with high precision to realize the centering maintenance of the back lining bearing. The mounting operation is convenient, the centering precision is high, the sealing property is good, the grinding precision is high, and the application range is extensive.

Description

Repair the precise centering fixture of back lining bearing

Affiliated technical field

The present invention relates to the anchor clamps of the high-accuracy bearing outside of machinery industry grinding outer ring, the particularly centralizer of grinding back lining bearing outer ring.

Background technology

Back lining bearing is mainly used in the backing roll on the exclusive 20 roller Sendzimir cold-rolling mills of making of Germany, and every unit is used back lining bearing 32 covers, is the exigent bearing of accuracy class.Metal and alloy thin band material, high accuracy band, thickness that Sendzimir mill is used for the rolling high-strength degree are 0.005～0.06mm band as thin as a wafer, and its roll-force passes to back lining bearing by working roll by first, second intermediate calender rolls.

Back lining bearing is the multiple row cylinder roller bearing, accuracy class is the P2 level, especially eliminate behind the end-play internal diameter to the depth of section H tolerance value particular importance of external diameter, H tolerance value on every axle all is controlled in the 0.005mm, and requires bearing outer ring precision Ke (Wall-Thickness Difference) to reach in the 0.003mm.

Domestic and international bearing industry is used for repairing all Shortcomings of the ripe technological process of the lasso mill processing of back lining bearing and basic fixed position method, is mainly manifested in the following aspects:

1, electric magnetic no-core clamp supporting: with the bearing top circle positioning component, the installation of supporting must be up to specification with adjustment; Main shaft required precision to lathe is higher, and rigidity requires stronger; The external diameter of the back lining bearing after the processing has scuffing, and Ke does not reach requirement, is not suitable for the fine finishining of back lining bearing.

2, pallet supporting: be applied in the positioning component on the centreless grinding machine external.Require supporting plate to have higher hardness and wearability; Applicable external diameter at 200mm with interior bearing machining; Be not suitable for the fine finishining of back lining bearing.

3, entity cylindrical mandrel: its machining accuracy depends on the precision of mandrel and the quality of fit between workpiece and mandrel, is difficult to reach the requirement of P2 level, is not suitable for the fine finishining of back lining bearing.

4, hydraulic stator mandrel: be to rely on certain pressure oil liquid to be filled between workpiece and the centering mandrel, and workpiece is floated centering, workpiece end face has contact roller to compress; Its full accuracy can only reach the P4 level, and this device is not suitable for the fine finishining of back lining bearing.

5, external supporting ringfeder mandrel: its machining accuracy makes bearing Ke about 0.003mm, because ringfeder and the centre bore in its mandrel easily collides with in the use procedure, and quick abrasion, the elasticity of ringfeder also can reduce in the use, thereby affects clamp precision and service life; Its precision is difficult to repair after the wearing and tearing, simultaneously the raceway dimensional tolerance range of back lining bearing is required in 0.03mm, and ovality Δ d1mp is in 0.003mm; The machining accuracy of its back lining bearing is difficult to obtain Reliable guarantee.

Summary of the invention

For overcoming the deficiencies in the prior art, the object of the present invention is to provide a kind of precise centering fixture of repairing back lining bearing, the design concept of bearing is applied in the jig Design, make the circular runout of anchor clamps reach 0.001mm, thereby the bearing Ke (Wall-Thickness Difference) after the reparation is reached in the 0.0015mm, and the accuracy class of bearing reaches the P2 level.

Technical program of the present invention lies in: bearing outer ring is in the outside of retainer, and steel ball is embedded in the window of retainer, it is characterized in that: driving lever is connected on the mandrel, for the mandrel that is rotatably connected on grinding machine; Mandrel becomes as a whole with the centering ring interference fit; One end of backstay is connected on the mandrel, and the other end inserts in the hole of limiting plate, and limiting plate is connected to an end of retainer with connector, is used for fixed retainer; Block is connected with retainer with connector, is used for making the bearing outer ring axial location; Stereosphere is enclosed within outside the steel ball of window of retainer, and the restriction steel ball rolls out; First, second sealing ring is contained in respectively in the groove of the external diameter of retainer and internal diameter, raceway, centering ring to bearing seal, the longitudinal cross-section of centering ring is dumbbell shaped, and there are peak, the alternate uniform circular arc of paddy in the radial circumference of its both sides scene-affinity and steel ball contact site; Baffle plate is connected to the retainer other end by elastomer with connector, prevents the bearing outer ring slippage.

The said limiting plate of the present invention is L shaped, and the hole of bottom is kidney-shaped, and backstay can be moved in the hole, when toggling it to an end in hole, is used for the bearing clamping to mandrel, and backstay is when the other end, and bearing is clamped on the mandrel by the radial load of steel ball.

During use, mandrel is centered on the grinding machine by the centre bore at its two ends, bearing holder (housing, cover) is on centering ring, radial load by steel ball is clamped on the mandrel, utilizes the Elastic approach minimum of accurate steel balls to reach 0.02mm, when maximum reaches 0.10mm, back lining bearing is positioned on the mandrel, and enough load is arranged in order to bear tangential grinding force, the external diameter of the high-accuracy bearing outside of grinding is realized the centering reparation to back lining bearing.

The present invention compared with prior art has the following advantages:

1, convenient mounting and clamping: several uniform circular arcs of design on the centering ring of mandrel, the combination of steel ball and circular arc is applied in the clamping, simple to operate, clamping efficient height;

2, centering precision is high: produce load when the present invention utilizes steel ball elasticity taxis amount, thereby make the bearing precision centering, and stop bearing to move radially;

3, good airproof performance: adopt double seal, prevent that effectively cutting fluid and abrasive dust from entering anchor clamps inside;

4, reconditioning precision is high: bearing outside diameter machining accuracy Ke after reconditioning reaches 0.0015mm;

5, the life-span is high: mandrel uses alloy nitrated steel technique, and hardness reaches more than the HV900, has improved centre bore wearability and life-span, and the mandrel centre bore passes through precise finiss, thereby has guaranteed the precision of mandrel;

6, applied range: back lining bearing raceway dimensional tolerance is in 0.10mm the time, and this centralizer all is suitable for.

Description of drawings

Fig. 1 is front view of the present invention;

Fig. 2 is the A-A cutaway view of Fig. 1;

Fig. 3 be the K of Fig. 1 to view, the reflection clamping position;

Fig. 4 be the K of Fig. 1 to view, the reflection operating position.

The specific embodiment

Dead man 1 is cylindric, and an end is threaded, and is two, is threaded with mandrel 2; Mandrel 2 is Step Shafts, there is accurate centre bore at two ends, two centre bores of mandrel 2 and grinding machine accurate top fixing, 2 rotations of grinding machine band moving mandrel, mandrel uses alloy nitrated steel technique, and hardness can reach more than the HV900, has improved centre bore wearability and life-span, the mandrel centre bore can guarantee the precision of mandrel through precise finiss; Backstay 3 is used for adjusting retainer 8 angles, and the one end is cylindric, is threaded, and is threaded with mandrel 2, and the middle part is cuboid, and the other end is cylinder, insert in the kidney slot of limiting plate 4, with limiting plate 4 are matched in clearance; Limiting plate 4 is planes of L-type structure, and kidney slot and two screwed holes are arranged, and is fixed on the retainer 8 with screw 5; Block 6 is cuboids, and two screwed holes and a cylindrical hole are arranged, and is fixed on the retainer 8 with screw 7, and cylindrical hole is used for inserting wrench, rotary clamp; Retainer 8 is hole class cylinders, and both ends of the surface have 6 screwed holes, and a plurality of axial cylindrical bore and 2 or 2 above ring belts are arranged, and is used for assembling spheroid steel ball 9, and steel ball 9 is matched in clearance with retainer 8, and there is respectively 1 ring belt at the two ends in retainer 8 inside and outside footpaths; Stereosphere 10 is enclosed within the outer ring of steel ball 9, and the restriction steel ball rolls out; Annular the first sealing ring 11, the second sealing ring 12 are embedded in respectively on the inside and outside footpath of retainer 8, with the cylindrical hole of retainer 8 are interference fit, by the flexible fastening of rubber on retainer 8; The internal diameter of centering ring 13 and mandrel 2 are interference fit, external diameter and retainer 8 are matched in clearance, the longitudinal cross-section of centering ring 13 is dumbbell shapeds, its endoporus and mandrel 2 interference fit, there are peak, the alternate uniform circular arc of paddy in the radial circumference of centering ring 13 both sides scene-affinitys and steel ball contact site, some sections concentric cambered surfaces of even distribution are namely arranged, and are concave surfaces between per two convex surfaces, and its angle is α °; Baffle plate 14 is with fluted, is fixed on the retainer 8 by screw 16, elastomer 15, is used for preventing 17 slips of back lining bearing outer ring, and elastomer 15 is folded spring.

As shown in Figure 3, when position shown in Figure 3 was arrived in α ° of backstay 3 band moving mandrels 2 rotation, namely steel ball 9 contacted with the concave surface of centering ring 13, and back lining bearing and centering ring 13 are matched in clearance, and steel ball 9 is at clamping position, and back lining bearing can easily be packed on the mandrel 2; As shown in Figure 4, when backstay 3 band moving mandrels 2 turn to position shown in Figure 4, steel ball 9 contacts with the convex surface of centering ring 13, back lining bearing and centering ring 13 are interference fit, steel ball 9 is in the operating position, at this moment, back lining bearing is fixed by the full payload that steel ball 9 produces, and just reaches to make the pinpoint purpose of back lining bearing.

The below calculates the full payload of anchor clamps generation and the tangential grinding force of grinding machine as an example of back lining bearing BCZ130 * 300 * 172.64C example, the load that produces when comparative analysis the present invention clamps is greater than tangential grinding force, load enough makes back lining bearing fix, and is loosening when stoping the back lining bearing grinding; And further discuss the present invention the raceway dimensional tolerance range of back lining bearing is required in 0.10mm.

It is as follows to calculate needed parameter:

The nodule number Z:12 of centring means

The columns i:2 of centring means

The sphere diameter Dw:23.813mm of centring means

(1) principal radius of curvature of steel ball:

$\mathrm{\ρ}1I=\mathrm{\ρ}1\mathrm{II}=\frac{1}{\mathrm{Dw}/2}=\frac{1}{(23.813/2)}=0.08398$

The principal radius of curvature of inner ring: ρ 2I=ρ 2II=0

So ∑ ρ=ρ 1I+ ρ 1II+ ρ 2I+ ρ 2II=0.1679

$F\left(\mathrm{\ρ}\right)=\frac{|\mathrm{\ρ}1I-\mathrm{\ρ}1\mathrm{II}|+|\mathrm{\ρ}2I-\mathrm{\ρ}2\mathrm{II}|}{\mathrm{\Σ\ρ}}=0$

The Elastic approach formula of steel ball and inner ring:

δ＝e _δ(∑ρ) ^1/3Q ^2/3

According to the hertz contact theory, try to achieve the size of contact-making surface:

e _a＝0.02363

e _b＝0.02363

πe _αe _b＝1.754×10 ^-3

e _δ＝1.754×10 ^-4

e _αThe oval major semiaxis coefficient of-contact-making surface

e _bThe oval semi-minor axis coefficient of-contact-making surface

π e _αe _bThe coefficient of-contact area

e _δThe coefficient of-Elastic approach

(2) try to achieve the full payload of steel ball according to Elastic approach:

$Q={\left(\frac{\mathrm{\δ}}{e_{\mathrm{\δ}}{\left(\mathrm{\Σ\ρ}\right)}^{1/3}}\right)}^{3/2}$

Known: steel ball smallest circumference Elastic approach δ _Always=0.02mm

δ _Single=0.005mm,

Try to achieve: single steel ball produces load Q=184N

Steel ball produces full payload Q _Always=4436N

Getting coefficient of friction is u=0.1

Steel ball can produce to the total circumferential pressure F of back lining bearing _Always=Q _AlwaysU=444N

(3) the average tangential grinding force of universal grinding machine external M1350 generation

$F_t=\frac{P_E{\mathrm{\η}}_E}{\mathrm{\π}{n}_s{d}_s}\×{10}^6$

P in the formula _E-grinding head motor actual measurement input power kw

η _E-electric-motor drive efficient generally gets 0.7～0.85

n _s-grinding wheel speed r/s

d _s-grinding wheel diameter mm

Known: P _E=6kw,

η _E＝0.85，

n _s＝1337r/s，

d _s＝500mm

Try to achieve: F _t=145N

F _Always=444＞F _t=145

The above load Q that produces of accurate centring means as can be known _AlwaysTangential grinding force F greater than emery wheel _t, load enough makes back lining bearing fix, and is loosening when stoping the back lining bearing grinding.

The maximum contact stress of accurate centring means generation of supposing back lining bearing is Pmax=4000MPa (steel ball does not lose the maximum stress that can bear of precision)

The load Qmax of the steel ball that produces is:

$Q\max ={\left(\frac{\mathrm{\ρ}\max \mathrm{\π}{e}_{\mathrm{\α}}{e}_b}{1.5{\left(\mathrm{\Σ\ρ}\right)}^{2/3}}\right)}^3$

Try to achieve according to above data: Qmax=3624N

The maximum single-piece Elastic approach of steel ball δ _Single=0.03mm

The maximum proof resilience convergence of steel ball amount δ _Always=0.12mm

Steel ball Elastic approach scope by the accurate centring means of above this back lining bearing of calculation specifications is 0.02～0.12mm, infer that this accurate centring means requires to that is to say that the raceway dimensional tolerance range of back lining bearing is carried out grinding at 0.10mm with interior this accurate centring means that can use in 0.10mm to the dimensional tolerance range of back lining bearing.

Claims (4)

1. precise centering fixture of repairing back lining bearing, bearing outer ring (17) is in the outside of retainer (8), steel ball (9) is embedded in the window of retainer (8), it is characterized in that: driving lever (1) is connected on the mandrel (2), for the mandrel (2) that is rotatably connected on grinding machine; Mandrel (2) becomes as a whole with centering ring (13) interference fit; One end of backstay (3) is connected on the mandrel (2), and the other end inserts in the hole of limiting plate (4), and limiting plate (4) is connected to a side of retainer (8) with connector (5), for fixed retainer (8); Block (6) is connected with a side of retainer (8) with connector (7), is used for making bearing outer ring (17) axial location; Stereosphere (10) is enclosed within outside the steel ball (9) of window of retainer (8), and the restriction steel ball rolls out; The longitudinal cross-section of centering ring (13) is dumbbell shaped, and there are peak, the alternate uniform circular arc of paddy in the radial circumference of its both sides scene-affinity and steel ball (9) contact site; Baffle plate (14) is connected to retainer (8) other end by elastomer (15) with connector, prevents bearing outer ring (17) slippage.

2. the precise centering fixture of reparation back lining bearing according to claim 1, it is characterized in that: said limiting plate (4) is for L shaped, the hole of bottom is kidney-shaped, backstay (3) can be moved in the hole, when toggling it to an end in hole, be used for bearing outer ring (17) clamping to mandrel (2), backstay (3) is when the other end, and bearing outer ring (17) is clamped on the mandrel (2) by the radial load of steel ball (9).

3. the precise centering fixture of reparation back lining bearing according to claim 1, it is characterized in that: the first sealing ring (11), the second sealing ring (12) are contained in respectively in the groove of external diameter, internal diameter of retainer (8), and raceway, the centering ring (13) of bearing sealed.

4. the precise centering fixture of reparation back lining bearing according to claim 1, it is characterized in that: said bearing is back lining bearing, the raceway dimensional tolerance range requires in 0.10mm.

Images